Heavily leaning on going with Hako violets but they are only available as 3-pin switches. Building a Plaid which is PCB-mounted. I’ve read that there are stability and alignment concerns so I thought I’d check and see if anyone can confirm or perhaps even provide tips on going this route.

It will be very difficult to exactly align all the switches without a plate. There is always a bit of space around the contacts of the switch.
If you choose to use 3-pin switches you need to be very careful.

Honestly, I wouldn’t even chance it. Without the two extra plastic pins attached to the PCB & no plate I feel like the switches would have too much movement. Most likely the pins coming from the actuation leaves would get bent back & forth so much they’d eventually end up snapping in half.